Validation Error for Block that Isn't in Use - Multisite Env

[tinamar]

I work with a pretty big multisite environment (45 sites) hosted with WP Engine. I work on a local environment, then push to staging (WPE Engine), then push to production. Currently, local and staging use WordPress 5.8, but I haven't updated production yet. On staging and local, the browser console shows the error below. Production does not show the error. The error shows in the page editor -- always. When I am adding a new page and haven't entered a title or added a block; when I open a page that doesn't have the block mentioned in the error; and when I'm working on a page that does use the block. The pages work fine. The block seems to work fine. But I'm kind of anal when it comes to errors and warnings in the console.

The error says that is was generated by the "Save" function. I believe it must be the autosave function as the error appears as soon as a new or existing page is loaded into the editor. No active "save" action as to take place.

This is the error/message from the console:

* BEGIN MESSAGE *
Block validation: Block validation failed for core/quote ({name: "core/quote", icon: {…}, keywords: Array(2), attributes: {…}, providesContext: {…}, …}).

Content generated by save function:

<blockquote class="viewport-display has-text-align-center wp-block-quote is-style-large"><p>"Contributing makes me feel like I'm being useful to the planet."</p><cite>— Anna Wong, <em>Volunteer</em></cite></blockquote>

Content retrieved from post body:

<blockquote class="wp-block-quote has-text-align-center is-style-large"><p>"Contributing makes me feel like I'm being useful to the planet."</p><cite>— Anna Wong, <em>Volunteer</em></cite></blockquote>
* END MESSAGE *

As you can see from the error/message, there is reference to some placeholder version of the quote block. But when I look in the template and block libraries, I see no such placeholder text. Neither the core quote block nor the core pullquote block (as seen in the block library) contains a placeholder quote by Anna Wong.

I searched the database. The main site (site #1) contains a couple of records in the _sitemeta table with this meta key: _site_transient_wp_remote_block_patterns_...

Those records contain the placeholder quote that appears in the error message.

The function generating the message gets printed to the file's output source:

function() {

window._wpLoadBlockEditor = new Promise( function( resolve ) {

wp.domReady( function() {

resolve( wp.editPost.initializeEditor(...

That function seems to be generated by wp-admin/edit-form-blocks.php

Since this error is only occurring on local and staging (which use v 5.8) and not on production (5.7.2) I'm reluctant to upgrade production right now.

Sorry for the long read... Anyone else experiencing this or know what to do about it?

Thanks!

[MrFlannagan]

We are experiencing the same thing at healthline on pantheon. Wanting to update from 5.7.2 to 5.8.* but this is preventing us from pushing to production. I do not understand why the system needs to ping api.wordpress.org/patterns/1.0 or why this is breaking our modified quotes block